KUG 1031+398

2RE J1034+396 was found in the ROSAT Wide Field Camera all-sky extreme-ultraviolet survey (Pounds et al. 1993; Pye et al. 1995). It was identified by Shara et al. (1993) and Mason et al. (1995) with the compact UV-excess 15.0 mag galaxy KUG 1031+398 (Takase & Miyauchi-Isobe 1987) at z = 0.042. This object has an intense soft X-ray emission with an unusually steep 2-10 keV power law of photon index $\Gamma \sim$ 2.6 $\pm$ 0.1 (Pounds et al. 1995) and an even steeper 0.1-2.4 keV power law with $\Gamma$ = 3.4 $\pm$ 0.3 (Puchnarewicz et al. 1995) or $\Gamma$ = 4.4 $\pm$ 0.1 (Rodriguez-Pascual et al. 1997).

UV spectroscopy with the Hubble Space Telescope shows the Ly$\alpha$ profile to be complex, with a narrow (400 kms^-1 FWHM) and a broad (1600 kms^-1 FWHM) component (Puchnarewicz et al. 1998). The optical continuum is not polarized (Breeveld & Puchnarewicz 1998).

The broad component of the Balmer lines is relatively narrow (FWHM $\sim$1500 kms^-1) and, consequently, this object has been classified as a NLS1 by Puchnarewicz et al. (1995). Narrow line Seyfert 1 galaxies are defined as Seyfert 1s having ``broad'' Balmer lines narrower than 2000 kms^-1 FWHM (Osterbrock 1987). Most NLS1s have a steep soft (< 1 keV) X-ray component and, conversely, most ultra-soft X-ray sources are associated with a NLS1 (Puchnarewicz et al. 1992; Greiner et al. 1996; Boller et al. 1996; Wang et al. 1996).